最近能源議題在全世界吵得沸沸揚揚，像是核能也是一個非常有爭議的能源議題，也很多人說要利用再生能源取代核能發電，而太陽能電池也是再生能源之一，所以如何降低太陽能電池的成本也是非常具有探討價值的議題，而本實驗為研究製作PERC太陽能電池，其中鈍化層為PERC太陽能電池一個很關鍵的部分，因此我們會對於如何沉積鈍化層進行研究。
本實驗使用硝酸鋁與尿素形成前驅物溶液，這兩種物質對環境危害較小，之後以溶液燃燒合成的方式進行氧化鋁之沉積，並在退火後形成氧化鋁鈍化層。此方法相較於使用真空設備沉積氧化鋁具有成本優勢，這種前驅物之溶液燃燒合成反應所產生之副產物為水、氮氣、二氧化碳、氧氣，也是對自然環境較無負擔之副產物。而我們會對前驅物的濃度跟比例、燃燒合成的時間與溫度、退火的時間與溫度進行測試，找出濃度為3 mM、硝酸鋁與尿素比為1:2.5、燃燒合成為350度10分鐘、退火為700度2分鐘最佳。接著沉積氮化矽保護氧化鋁薄膜，再進行第二次退火以400度10分鐘為最佳。之後利用黃光製程在太陽能電池背後蝕刻柵狀線條後再進行網印與燒結即可完成太陽能電池。之後以TEM測量氧化層厚度，再進行CV量測計算出負電荷密度，最後以最佳參數完成之太陽能電池最高轉換效率達到16.86%，比全面鋁之太陽能電池高了0.40%。

Recently, energy issues have been intensively discussed globally. For example, nuclear energy is one of controversial issues, due to the potential harm to the environment and mankind. Many people thus hope to use renewable energies as an alternative choice of energy. And one of renewable energy is solar energies. Therefore, how to reduce the cost of solar cells becomes a very important issue for manufacturing cost-effective solar cells. The purpose of the study here is to find environment friendly materials to form passivation layers for PERC solar cells. That is, we will study how to deposit a passivation layer on the rear side of a PERC solar cell.
In this study, we choose 〖Al(NO〗_3 )_3 and CO(NH_2 )_2 as the precursors because the two substances impose less harm to environment. To make an aluminum oxide film with the two substances, a method of aqueous combustion synthesis is used. This makes feasible a cost-effective deposition process, which compares favorably with the conventional deposition method with vacuum equipment used. After annealed, a passivation layer of AlO_x is successful formed on the rear side of a solar wafer. First, we will test the concentration and ratio of the precursors, the time and temperature of aqueous combustion synthesis, and the annealing time and temperature. Finally, we find out that the concentration is 3 mM, the ratio of 〖Al(NO〗_3 )_3 and CO(NH_2 )_2 is 1:2.5. The best temperature and time of aqueous combustion synthesis are 350°C and 10 minutes, respectively. Annealing the AlO_x film at 700°C for 2 minutes is the best. Subsequently, a silicon nitride layer is deposited on the rear side to protect the aluminum oxide film from the impact of moisture and decay of the film’s property. And then we apply a second-time annealing at 400°C for 10 minutes to repair the defects after deposition of the silicon nitride layer. The thickness of the aluminum oxide layer is measured by TEM, and the negative charge density is calculated by CV measurement. Finally, the highest efficiency of the PERC solar cell is 16.86%, which is 0.40% higher than that of the best Al-BSF solar cell fabricated here.

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